NAME

dummy-ups - Driver for multi-purpose UPS emulation

NOTE

This man page only documents the specific features of the dummy-ups driver. For
information about the core driver, see nutupsdrv(8).

DESCRIPTION

This program is a multi-purpose UPS emulation tool. Its behavior depends on the running
mode:
DummyModedummy-ups looks like a standard device driver to upsd(8) and allows one to change any
value for testing purposes. It is both interactive, controllable through the upsrw(1) and
upscmd(1) commands (or equivalent graphical tool), and batchable through script files. It
can be configured, launched and used as any other real driver. This mode is mostly useful
for development and testing purposes.
RepeaterModedummy-ups acts as a NUT client, simply forwarding data. This can be useful for supervision
purposes. This can also allow some load sharing between several UPS instances, using a
point-to-point communication with the UPS.

IMPLEMENTATION

The port specification depends on the running mode, and allows the driver to select the
right mode.
DummyMode
Port is a definition file name for dummy-ups. This can either be an absolute or a relative
path name. In the latter case the NUT sysconfig directory (ie /etc/nut,
/usr/local/ups/etc, ...) is prepended.
For instance:
[dummy]
driver = dummy-ups
port = evolution500.dev
desc = "dummy-ups in dummy mode"
This file is generally named "something.dev". It contains a list of all valid data and
associated values, and has the same format as an upsc(8) dump (<varname>: <value>). So you
can easily create definition files from an existing UPS using "upsc > file.dev". It can
also be empty, in which case only a basic set of data is available: device.,driver.,
ups.mfr, ups.model, ups.status
Samples definition files are available in the "data" directory of the nut source tree, and
generally in the sysconfig directory of your system distribution.
Since dummy-ups will loop on reading this file, you can dynamically modify it to interact
with the driver. This will avoid message spam into your system log files, if you are using
NUT default configuration.
You can also use the "TIMER <seconds>" instruction to create scheduled events sequences.
For example, the following sequence will loop on switching ups.status between "OL", "OB"
and "OB LB" every minute:
ups.status: OL
TIMER 60
ups.status: OB
TIMER 60
ups.status: LB
TIMER 60
It is wise to end the script with a TIMER. Otherwise dummy-ups will directly go back to
the beginning of the file.
RepeaterMode
Port is the name of a remote UPS, using the NUT form, ie:
<upsname>[@<hostname>[:<port>]]
For instance:
[repeater]
driver = dummy-ups
port = ups@hostname
desc = "dummy-ups in repeater mode"

INTERACTION

Once the driver is loaded in dummy mode, you can change any variables, except those of the
driver.* and server.* collections. You can do this by either editing the definition file,
or use the upsrw(1) and upscmd(1) commands.
Note that in simulation mode, new variables can be added on the fly, by adding these to
the definition file. Conversely, if you need to remove variable (such as transient ones,
like ups.alarm), simply update these by setting an empty value. As a result, they will get
removed from the data.
In repeater mode, the driver acts according to the capabilities of the UPS, and so support
the same instant commands and settable values.

BACKGROUND

This driver was written in one evening to replace the previous dummycons testing driver.
It was too limited and required to work from a terminal to interact.
dummy-ups is useful for NUT client development, and other testing purpose.
It also helps the NUT Quality Assurance effort, by automating some tests on the NUT
framework.
It now offers a repeater mode. This will help in building the Meta UPS approach, which
allows one to build a virtual device, composed of several other devices (either UPS,
PDUs).

BUGS

Instant commands are not yet supported in Dummy Mode, and data need name/value checking
enforcement, as well as boundaries or enumeration definition.